Cake Sizes?

I have a question that will probally make everyone think I'm nuts. I get the sheet cakes confused. I have a 11 x 15 pan and a 12 x 18 pan. I was wondering if anyone could tell me what size is a full sheet, a half sheet and a so on. I have a few orders coming up and they are ordering the cakes like this and I have no idea what pan to use. Thanks for taking the time to look and have a good weekend.

If someone asks "HOw much for a full sheet cake?", if you ask them "how big is that?" or "How many does that serve?" you'll get answers that range from 10 to 100..... the public has NO IDEA how big those cakes are. THey just use the lingo without knowing what they are ordering.

I love screwing with their minds! Someone wants a price on a "full sheet cake" and I tell them $230. When they gasp, I reply, "You did say a FULL sheet cake .... did you need a 22x28 that serves 150 people?"

So .... someone asks for pricing on a half or a full sheet cake, I bypass their question and ask them how many people they need to serve. Then I tell them what size cake they need to order.